1. Field of the Invention
The present invention relates to alumina/zirconia ceramics and a method of producing the same. More specifically, the invention relates to alumina/zirconia ceramics having a high strength, a high toughness and a high abrasion resistance suited for use as structural parts, and to a method of producing the same.
2. Background Art
Owing to their excellent mechanical properties and corrosion resistance, ceramics have, in recent years, been used for a variety of structural parts such as various blades, tools, mechanical parts like bearings and members related to living bodies. As ceramics suited for these applications, Japanese Examined Patent Publication (Kokoku) No. 7-64631 discloses zirconia-type composite ceramics containing a zirconia crystal phase stabilized by CeO2 and Y2O3 and containing an alumina crystal phase, the zirconia crystal phase in the composite ceramics chiefly comprising tetragonal crystals exhibiting excellent mechanical properties such as strength and toughness, and excellent resistance against the hydrothermal aging.
The zirconia-type composite ceramics disclosed in the above Japanese Examined Patent Publication is a zirconia-rich sintered body containing alumina in an amount of 3 to 60% by weight per the stabilized zirconia and having an average crystal particle size of not larger than 3 μm, and features a high flexural strength, a high toughness and a high resistance against the hydrothermal aging, but has a low hardness and a low abrasion resistance.